> Waiting happens to occur "in parallel" when using async I/O. > and you don't run two sync OS I/O calls in parallel. you can run sync IO calls and wait for ea

> Waiting happens to occur "in parallel" when using async I/O. > and you don't run two sync OS I/O calls in parallel. you can run sync IO calls and wait for each in separate threads. the GIL is released for IO. the waiting is "in parallel" just as much with a threaded / blocking approach as with a non-blocking.